As prior art documents for this type of the plant cultivation device, there can be mentioned Patent Document 1 which is shown below. The plant cultivation device described in Patent Document 1 includes: a nozzle for watering a plant in a pot with water in a water tank from above; and a moisture sensor for detecting a moisture amount in soil where plant is grown, and performs watering from the nozzle based on a detection value of the sensor. It alleges that, therefore, the plant will not die due to deficiency of water, even after a long-term absence of care.